S.C. Code § 40-49-210
In each county in this State with a population of more than one hundred fifty thousand, according to the most recent official United States census, the governing body of the county may determine the areas or sections in the county in which, by reason of density of settlement or population, rules and regulations for the construction of all plumbing and sewerage placed in or on any building or the premises thereof in such area or section are necessary for the protection of public health and safety and such body may, either by resolution or ordinance, provide and prescribe reasonable rules and regulations for the construction of all plumbing and sewerage placed in or on any building or the premises thereof in any such area or section which such body shall deem to be necessary and proper for the protection of public health and safety in any such area or section.
S.C. Code § 40-49-210